China has abundant crop germplasm resources. At present, 340 crops and a total of 490,000 accessions have been conserved at the national conservation system. How to ensure the safe conservation of germplasm resources is the responsibility and mission of genebank managers. Since the Ninth Five-Year Plan, the National Crop Genebank of China has systematically studied the theories and technologies of the safe conservation of germplasm. For the first time, we proposed a theory for germplasm resources conservation, including both safety backup and the biological mechanism of conservation. The transition from platform (high viability) to the rapid reduction phase of the seed survival curve was defined as the critical node (CN). It was revealed that oxidative damage and mitochondrial damage disorder the metabolism in the CN. In addition to, there was demonstrated that regeneration threshold values is the CN according to that the accession was regenerated when its germination rate was lower than the CN, resulting in the loss of genetic integrity. Taking loss of viability and genetic integrity together, safe longevity of germplasm is the period from the beginning of storage to the time point when seed viability declined to the CN. We have made breakthroughs on the key techniques for seed viability monitoring, early warning of viability decline, regeneration and in vitro preservation. Based on the above research, we have created a technological system for the safe conservation of crop germplasm resource, which has been applied in Chinese genebanks. For avoiding the loss of germplasm resources due to the loss of vigor and genetic integrity in genebank, the technological system would prolong the safe longevity of accession, monitor and forecast the accession viability, recognize the accession which needs to be regenerated. Therefore, the technological system provides a reliable guarantee for the safe conservation of crop germplasm resources in China.